A conventional method for making an integral bicycle frame generally requires a mold set including an upper mold and a lower molds and each of which has concavities so that the metal bicycle frames such as aluminum frames are formed in the concavities. However, the bicycle frames requires a large mold set and the cost of the mold set is expensive. The bicycle frames may have different sizes and each size needs a mold set so that the expense for the mold sets of different sizes is a heavy load for the manufacturers.
The present invention intends to provide a method for making a bicycle frame with movable mold parts which can be arranged at desired position so as to manufacture the bicycle frames of different sizes.